A liquid pressure transfer is known, in which a transfer film made by applying an appropriate water-insoluble transfer pattern with transfer ink on a water-soluble film (holding sheet) in advance is set in the transfer tank (transfer liquid) so that the transfer film floats on the transfer liquid, and while the transfer film (water-soluble film) is wet with the transfer liquid (in short, water), the object is pressed onto the liquid in the transfer tank while the object is brought into contact with the transfer film, and using the liquid pressure, the transfer pattern on the film is transferred and formed on the surface of the object. As described above, on the transfer film, the transfer pattern is formed (printed) on the water-soluble film with ink in advance, and the ink of the transfer pattern is in a dried state. Therefore, during the transfer, it is necessary to apply an activating agent, a thinner, and the like to the transfer pattern on the transfer film to return the transfer pattern back to a wet state like the state immediately after the printing of the transfer pattern, i.e., to return the transfer pattern back to a state achieving the adhesive property, and this is referred to as activation.
Then, after the transfer, the half-dissolved water-soluble film is removed by water-cleaning and the like from the object removed from the transfer tank, and thereafter, the object is dried. In order to protect the decorative layer formed and transferred onto the object, the object is subjected to top coating in many cases. However, in this kind of conventional liquid pressure transfer, first, solvent-based clear coating is used for the top coating, and there is a problem in that the environmental impact is high, and moreover, since, e.g., there is a defect during the top coating and it takes a relatively long time and energy in the coating and drying, the overall cost of the liquid pressure transfer increases.
Therefore, a method has been devised, in which during the liquid pressure transfer, a transfer pattern also having a surface protection function is formed on an object, and after the transfer, this is cured to form a decorative layer, so that the top coating is omitted (for example, see Patent Literatures 1, 2).
Among them, Patent Literature 1 relates to a method in which, while a conventional transfer film made by forming only a transfer pattern on a water-soluble film is used, a curable resin composition (liquid) is used as an activating agent, and ultraviolet rays are emitted onto the object after the transfer, so that a curable resin composition (surface protection layer) formed integrally with the transfer pattern is cured.
On the other hand, Patent Literature 2 relates to a method in which a transfer film made by forming a curable resin layer between a water-soluble film and a transfer pattern is used, and the curable resin layer on the transfer pattern is cured by emitting active energy rays such as ultraviolet rays onto the object or heating the object after the transfer.
By the way, in the liquid pressure transfer, when the object is immersed into the liquid (during the transfer), such operation is performed that the object pierces through the transfer film floating on the surface of the liquid and sinks into the liquid, and for this reason, after the object sinks into the liquid, the film remaining on the surface of the liquid is no longer used for the transfer and is unnecessary (this will be referred to as liquid surface residual film).
When the object pierces through the transfer film on the surface of the liquid, a large amount of very small film residues (for example, in a form of waste strings made up with the water-soluble film and the ink which are mixed) are dispersed and discharged into the transfer liquid, and these are accumulated in the transfer liquid.
Usually, the object is immersed into the liquid (transferred) with a jig attached thereto, and when the object is immersed into the liquid, redundant films attached to the jig and the object may be separated and discharged in the liquid.
For this reason, the liquid surface residual films, the film residues, the redundant films, and the like explained above may attach to the design surface of the object pulled up from the transfer liquid (these remain in the liquid and the transfer liquid surface and are unnecessary after the transfer, and therefore, in this specification they are collectively referred to as “foreign substances”).
Further, for example, as shown in FIG. 19(a), in a case where the object W has an opening portion Wa in the design surface S1, a thin film M made of a water soluble material of the water-soluble film is often formed in the opening portion Wa when the object is pulled up from the surface of the liquid, and this bursts, whereby bubbles A attach to the design surface S1 of the object W, or when the transfer liquid L drops to the surface of the liquid from a protruding portion of the object W or an upper edge portion of the opening portion Wa, bubbles A are generated on the surface of the liquid, and the bubbles may attach to the design surface S1. More specifically, in FIG. 19(a), at first, the thin film M is formed in the frame of the jig J, and the burst residual bubbles A float on the surface of the transfer liquid L. According to the movement of the surface of the liquid in the liquid-leaving area P2 (relative descend as the object W is pulled up), the bubbles A are incorporated into the thin film M formed in the opening portion Wa of the object W. Thereafter, the burst residues of the thin film M float on the surface of the liquid as the bubbles A, and the bubbles A indirectly attach to the design surface S1, or the bubbles A are directly passed along the surface of the object W, and attach to the design surface S1. As a result, the state as shown in FIG. 19(b) is obtained.
Then, when curing processing is performed by emission of active energy rays and/or heating in this state, for example, as shown in FIG. 19(c), the following defects occur. Only in portions to which the bubbles A attach, a defect of deformation of the pattern of the decorative layer (the transfer pattern and the surface protection layer) and a defect (so called pinhole defect) of loss of the pattern may occur in the portions occur because of the reasons such as stress caused by the bubbles A and refraction caused by the active energy rays. It is to be understood that the above defect of the deformation of the pattern and the defect of the loss of the pattern are not limited to a case where the bubbles A attach to the object W. This is a phenomenon that may also occur when foreign substances such as the liquid surface residual films, the film residues, and the redundant films attach to the design surface S1. In this case, reference numeral f in the figure mainly denotes the decorative layer transferred to the object W (design surface S1) and the like. Therefore, during the liquid pressure transfer, it is particularly important to prevent the liquid surface residual films, the film residues, the redundant films, the bubbles A, and the like from attaching to the design surface S1 as much as possible in the liquid pressure transfer for forming the transfer pattern also having the surface protection function. It should be noted that a product with the defect of pattern deformation and/or the defect of pattern loss (liquid pressure transfer product) are once subjected to the curing processing, projection and depression caused by the pattern deformation and the pattern loss are significant, but it is impossible to perform the transfer all over again (impossible to reproduce), and therefore, the above defects significantly reduces the mass productivity, and a fundamental solution method for reducing the defective rate itself is strongly desired.
It is to be understood that the liquid surface residual films floating on the surface of the liquid after the transfer have been collected in the past, and, for example, the overflow structures provided at the end of the transfer tank are used to collect them. More specifically, this is a method in which, after the transfer, the liquid surface residual films as well as the transfer liquid are caused to flow into the overflow tanks at the end of the transfer tank, and when the transfer liquid collected there are used for recycle, the liquid surface residual films are removed and collected by a filter and the like provided in a path.
However, in this kind of collecting method, the liquid surface residual films pass through the liquid-leaving area. Therefore, in particular, in liquid pressure transfer for forming even a surface protection layer during liquid pressure transfer, this collecting method cannot be said effective collection means, and more active collecting method is desired, and there is such method that has already been devised (for example, in addition to Patent Literature 2 explained above, see Patent Literatures 3 and 4).
First, Patent Literature 2 discloses a method in which every time the liquid pressure transfer is performed, all residual films on water surface are pushed and washed away from a transfer tank by providing water into the tank from a bottom portion of the transfer tank. On the other hand, Patent Literature 3 discloses a method for sucking films on water surface using vacuum while an object is immersed under the water. Further, Patent Literature 4 discloses a method, in which after an object is pulled up from a water tank, air is blown to one end of the water tank, and transfer residues and remaining residues are washed away from the one end of the water tank after an ink coat is transferred onto the object.
However, these are mainly intended for collecting films and residues on the transfer liquid surface (on the water surface). Moreover, these require extensive structure, and are batch processing method in which films and residues are collected on every transfer, and therefore, it takes a long time and the efficiency is low, which cannot be necessarily said a preferable method.